Draft gear



H. L. SPENCE Jan. 9, 1934.

DRAFT GEAR Filed Deo. 51, 1930 2 Sheets-Sheet 2 H/fl/ mmlllml PatentedJan. 9, 1934 DRAFT Hubert L. Spence, East Cleveland, Ohio,

GEAR

assigner to National malleable & Steel Castings Company, Cleveland, ho,

a corporation of Ohio Application December 31, 1930 Serial No. 505,759

6 Claims.

lIhis invention is concerned with the provision of a novel and improvedrailway draft gear. The invention includes a novel arrangement andrelationship of springs for cooperating with wedgng and frictionelements, whereby not only is a high frictional and spring capacityattained but also wear upon the springs and housing is obviated. A morespecific feature of the invention comprises the provision of springseating or follower means cooperating with a group of springs forenabling the latter to oppose movement of friction shoes and at the sametime, through its cooperation with the central spring of the group,preventing engagement of others of said springs with the wall of thedraft gear case. Other features of the invention will be hereinafter deuscribed and claimed.

In the accompanying drawings:

Fig. 1 is a longitudinal vertical sectional View of a draft gearembodying my invention, said view being taken on line 1 1 of Fig. 3.

Fig. 2 is a horizontal sectional View thereof taken on line 2 2 of sig.4.

Fig. 3 is a transverse vertical section taken on line 3-3 0f Fig. 1.

Fig. 4 is a transverse vertical section on line 4-4 or" Fie. 2.

Fig. 5 is a detail View in front elevation of a spring follower.

Fig. 6 is a detail View, partly in plan and partly in horizontalsection, of said follower, and

Fig. I is a detail view in vertical section on line 7 7 of Fig. 5.

Referring to the drawings, the gear comprises a case 2, preferablyrectangular in form, in opposite walls 3 of which are seated thefriction members 4, each of which ispreferably a rectangular blockhaving at its inner end a lateral projection 5. In each wall 3 is arecess 6 in which the projection 5 of the associated friction member lis seated. To resist the inward thrust of the friction members 4, thecase 2 at the rear of the recesses 6 has abutments 6 against which themembers 4 bear at their rear ends, and said abutments 6' are braced byribs 7 which extend back to and are merged into the rear end 8 of thecase.

On opposite sides of each of the friction members 4 and in frictionalengagement therewith are arranged friction shoes 9, two friction membersand four shoes being provided. The inclined forward faces of the shoes 9are engaged by correspondingly inclined faces 10 of a wedge member 11.Each shoe face has also an inclined recess 12 into which nts acorrespondingly inclined rib or ange 13 on the wedge 11 for the purposeof maintaining the shoes and wedging faces in alignment and ofpreventing the shoes 9 from working laterally over to and abrading thesides of the case 2.

Mounted centrally within the case 2 and ex- 5o tending along thelongitudinal axis thereof is a coil spring 14, which engages the rearwall 8 of the case 2 at one end and at its other end engages a pair ofspring seat members or followers l5, 15, each oi' which spring seatmembers engages the 65 rear faces 16 of the projections 17 of a pair ofthe shoes 9. Each spring seat member extends from a shoe cooperatingwith one of the friction inembers 4 to a shoe cooperating with the otherof said friction members. Surrounding the central spring 14.- aforesaidare four springs 18, one for each shoe i?, and positioned in therespective corner portions of the case, as shown in Fig. 3. Each of saidsprings 18 bears at its rear end against the end wall 8. At theirforward ends, two of said springs engage one of the spring seat members15 and the other two of said springs engage the other of said springseat members.

Each of the spring seat members 15 is provided with a pair of rearwardlyextending projections or bosses 19 which extend into the coils of theassociated springs 18 and thereby maintain said coils in a definiterelation to the spring seat member. I further construct each of saidspring seat members with a built out or extended portion 20 having a lipor projection 21 which eX- tends into the interior of the coil spring14. Said projection 21 is curved, as shown, to conform with thecurvature of said coil. Through the engagement of the projections 21 ofthe respective 90 spring seat members 15 with the interior of the coilof spring 1li said seat members are prevented from shifting to suchextent as to permit the springs 13 to engage the walls of the case 2. Itwill be une erstood that the dimensions of the parts are such that theseresults will be accompiished. In other words through the spring seatmembers and their cooperation with the central spring 141 the springs 18are retained in a denite relation to said central spring and aremaintained out of engagement with the walls of the case 2; and I thusobviate the possibility of objectionable wear between said walls andsaid springs 18. Furthermore, in the construction i1- lustrated, thespring 14 is maintained against 195 undesired lateral displacement byengagement with projection 21, which in turn engages bolt 22. Also, theextended bearing 20 which I provide between the seat members 15 and thecentral spring 110 14 minimizes wear between that spring and saidmembers.

The case 2 and wedge 1l are maintained in assembled relation by a bolt22, which is engaged at its rear end with an opening in the wall 8 ofthe case and at its forward end extends through an opening in a centralprojection 23 of the wedge. A nut 24 is threaded on said bolt within therecessed portion 25 of said projection. The spring seat members orfollowers l5 are cut away or notched as shown at 26 for accommodatingthe bolt 22. Said spring seat members are also provided on their frontsurfaces with upper and lower reinforcing ribs 27, 28, as shown.

It will be seen that compression of the gear is resisted by the springs14 and 18, and by the friction generated between the shoes 9 and theassociated friction members li. Said shoes, under the influence of thewedge surfaces 10 and the action of the springs 14 and 18, aremaintained in firm frictional engagement with the friction membersduring the compression of the gear. The amount of friction developedbetween the shoes and friction members is dependent on the angle ofinclination of the sides or faces of the friction members to thelongitudinal axis of the gear. 'Ihe faces of said friction members maybe inclined at any suitable angle or may be parallel to saidlongitudinal axis of the gear. When the pressure on the gear abates theparts are returned to their normal positions by the action of thevarious springs.

The extent of movement of the wedge with respect to the case is suchthat just before the springs go solid the peripheral flange 29 of thewedge will engage the front end of the case.

While I have shown the projections 5 of the friction members in firmengagement with the openings 6, a limited amount of clearance may beprovided between said openings and projections. In this way the initialcompression of the gear may be opposed simply by the springs 14 and 18and further compression thereof both by said springs and by the frictiondeveloped between the shoes and friction members. The extent ofpreliminary spring action may be varied by varying the amount of saidclearance, and the capacity of the springs.

The terms and expressions which I have employed are used as terms ofdescription and not of limitation, and I have no intention, in the useof such terms and expressions, of excluding any equivalents of thefeatures Shown and described or portions thereof, but recognize thatvarious modifications are possible within the scope of the inventionclaimed.

I claim:

1. In a draft gear, a case, friction members within said case; aplurality of pairs of friction shoes, each of said pairs being infrictional engagement with a corresponding one of said members; aplurality of springs, one for each of said shoes for resisting movementof said shoes, said springs extending longitudinally of said caseadjacent the walls thereof, a pair of spring seat members, one of whichis interposed between Icertain of said shoes and the correspondingsprings, and the other of which is interposed between others of saidshoes and the springs corresponding thereto, each of said spring seatmembers having projections engaged by the associated springs formaintaining the latter in a given relation to the spring seat members; aspring positioned centrally in said case and engaging both seat members;and projections on said seat members extending within the coil of thelast mentioned spring.

2. In a draft gear, a case, cushioning means comprising springsextending substantially the length of said case, certain of said springsextending adjacent the side walls of the case, and another of saidsprings being positioned in a central portion of the case, frictionelements mounted in said case in spaces between said springs, shoesengaging said friction elements, and spring seating means interposedbetween said shoes and springs, said spring seating means having meanscooperating with said spring for maintaining all of said springs in agiven relation to each other.

3. In a draft gear, a case, friction means in said case comprisingfriction shoes, a wedge engaging said shoes, springs extendinglongitudinally in said case adjacent the walls thereof and resistingmovement of said shoes, a plurality of spring seat members eachinterposed between respective ones of said shoes and the correspondingsprings, a spring positioned centrally in said case and engaging saidspring seat members for resisting movement of said shoes, and aretaining bolt engaging said wedge and said case and extending throughthe interior of the coil of said centrally positioned spring and betweensaid spring seat members, each of said spring seat members interlockingwith said central spring and one of said other springs to maintain saidsprings in proper spaced relation.

1. In a draft gear, a rectangular case, a spring in each corner of saidcase, a member engaging an end of each of a pair of said springs, asecond member engaging an end of each of another pair of said springs, aspring positioned centrally of said case and means on said membersengaged with said central spring for maintaining said pairs of springsin a given relation to eachother.

5. In a draft gear, a case, a plurality of pairs of springs in saidcase, means joining the springs of one pair and separate means joiningthe springs of another pair of said springs for holding the springs ineach pair a given distance apart, a central spring positioned betweensaid pairs of springs, and means on said joining means engaging said`central spring for preventing separation of said pairs of springs.

6. In a draft gear, a case, friction means in said case comprisingfriction shoes, a wedge engaging said shoes, springs extendinglongitudinally in said case adjacent the walls thereof and resistingmovement of said shoes, a plurality of spring seat members eachinterposed between respective ones of said shoes and the correspondingsprings, and a spring positioned centrally in said case and engagingsaid spring seat members for resisting movement of said shoes, each ofsaid spring seat members interlocking with said central spring and oneof said other springs to maintain said springs in proper spacedrelation.

HUBERT L. SPENCE.

